In a mostly ho-hum night at the Emmys, Glenn Weiss delivered a moment that left most of those in attendance slack-jawed and applauding.

He proposed to his girlfriend, Jan Svendsen, on live television after winning an Emmy.

Mr. Weiss, who has now amassed more than a dozen Emmys, won for outstanding directing for a variety special for his work on the most recent Oscars. He’s a veteran of Hollywood-centric television events, having helmed events as varied as the Kennedy Center Honors and the Macy’s 4th of July Spectacular.

He started his speech paying tribute to his mother, whom he said had passed away two weeks ago.

“Part of my heart is broken,” said Mr. Weiss, 57. “I don’t think it will ever be repaired.”

He added: “Mom always believed in finding the sunshine in things and she adored my girlfriend Jan.”

“Jan, you are the sunshine in my life,” he continued. “And mom was right, don’t ever let go of your sunshine. You wonder why I don’t like to call you my girlfriend? Because I want to call you my wife.”

Ms. Svendsen’s jaw dropped — as did several in the audience — and she said yes before he even popped the question. The crowd began to cheer as Ms. Svendsen, the chief creative officer at the Charity Network, walked to the stage. Mr. Weiss told her when she arrived, “This is the ring that my dad put on my mom’s finger 67 years ago. And to my sisters and brothers, I didn’t swipe it. Dad knows I have it, O.K.?”

He got on one knee and said, “Jan, I want to put this ring that my mom wore on your finger in front of all these people and in front of my mom and your parents watching from above. Will you marry me?"

She, of course, said yes, and the two walked offstage with an Emmy and a lifetime partnership.

Speaking to reporters after the show, Mr. Weiss said the couple met in 2001 while working together, and that they had been together for 10 years. He said he did not tell anyone about his proposal plans except his father, since he was the keeper of his mother’s ring.

“Now it’s where it belongs,” Mr. Weiss said.

Emmys producers, like the viewers, were in the dark. Mr. Weiss said he considered warning them, but the director of the show, Hamish Hamilton, was nominated in the same category so it would have been a bit awkward, he said.

Ms. Svendsen, who was the chief marketing officer for the Tony Awards, said they were used to attending a lot of awards shows, so she was not expecting anything unusual — certainly not a proposal.

“I really hoped he was going to dedicate the award to his mother,” she said. “He did, and then some.”